x INTRODUCTION. 



form is here omitted, as it has been shown to have no claim to 

 a place in the British list, into which it had been introduced on 

 the strength of museum specimens. 



Fishes. It is fortunate so far as the classification and 

 nomenclature are concerned that the list of British Fishes can be 

 based upon reliable and satisfactory authority. The classification 

 adopted is that promulgated by Dr. Giinther in his recently pub- 

 lished Introduction to the Study of Fishes '; while his well-known 

 ' Catalogue of Fishes ' furnishes a safe guide to the nomenclature. 

 Dr. Day's papers in the Linnean Society's Journal, and more 

 particularly his comprehensive work on the 'Fishes of Great 

 Britain and Ireland,' have also served as a guide to some of the 

 conclusions arrived at. 



The British Fishes here enumerated are substantially those of 

 the third edition of YarrelPs 'History of British Fishes' (1859), 

 modified by the assistance of the writings of the two distinguished 

 ichthyologists just referred to. Some few, however, of the species 

 included by Yarrell, and a considerable number of those added 

 by Couch, have since the date of their writings proved to be 

 either monstrosities, varietal or immature forms of other species, 

 or to have been admitted into the British fauna on insufficient 

 evidence. Their omission consequently requires no further 

 explanation. 



In attempting to define the faunistic position of fish, not only 

 is there found a deficiency of the requisite information for the 

 Yorkshire coast, but considerable dissatisfaction is the usual 

 result of a reference to the works of Yarrell and Couch. 

 Admirable as they are in certain respects, the vagueness of 

 some of the statements made, and the want of system in the 

 arrangement of the subject-matter, often renders it extremely 

 difficult to ascertain the geographical range of a species, still more 

 so to learn its true position in the British fauna. This remark 

 applies even in the case of some of the commonest forms. It is 

 true that the habits of fishes are very obscure and their natural 



